Piston for gasoline engines



16, 1933- J. N. LITTIRELL 1,909,775

PISTON FOR GASOLINE ENGINES Filed Jan. 25, 1932 INVENTOR WITNESSES:

W @M/M Patented May 16, 1933 UNITED STATES PATENT OFFICE JOHN N. LITTRELL, OF LOUISVILLE, KENTUCKY, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, OF ONE-FOURTH TO ROBERT G. GOODIN, ONE-FOURTH TO AGNES GOODIN, AND ONE-FQUR-TH T0 0. J. PASS, ALL OF LOUISVILLE, KENTUCKY PISTON FOER GASOLINE ENGINES Application filed January 23, 1932. Serial No. 588,252.

My invention relates to pistons in general, or short cylinders provided with solid heads, fitting into cylindrical vessels and adapted to slide back and forth thereineither moved by,

or moving against, fluid pressure in the cylindrical vessels; and my invention consists of a short cylinder provided with a solid head, having the usual annular grooves around thehead adapted to hold ordinary piston packing rings, and further provicledwith a skirt divided into two equal parts, one part being inte 'ral with the head and the other part being adjustable to compensate for the wear in usual service. And the general object of my invention is to provide a serviceable piston that" can be adjusted from time to time to a certain extent to compensate for the usual wear in service, either along the outer sides of the skirt of the piston or along the inner walls of the cylindrical vessel in which the piston slides, so that the piston may be efliciently used for a longer time than the ordinary piston. And a special object of my invention is to design a piston whose side adjustments may be made at right angles to the axis of the wrist-pin on the two sides subject to the greatest wear. Another object of my invention is to provide compensating adjustments adapted to set and hold the cylindrical sur face of the movable part of the skirt parallel with the cylindrical surface of the integral part of the skirt in normal operation.

All of these objects are attained in my present invention; and my new and useful piston for gasoline engines illustrated in the accompanying drawing which forms a part of this specification, is a practical apparatus embodying the aforesaid novel means and other tion of my new piston assembled ready for In service, but without the packing rings. this view are shown the end of the wrist-pin and a fragment of the connecting rod in their operative positions. Also, the seam between the movable and the integral parts of the piston skirt is shown close Figure II is a vertical projection of the inside of my piston with the wrist-pin and the connecting rod removed to show clearly the plan View of the lower and the two upper adj ustment brackets which are integral, with the movable part of the piston skirt and which are here shown secured in their original or innermost operative position by means of threaded studs and clamping nuts set thereon, the seams or joints between the movable part and the integral or stationary part, of the piston skirt being closed. The journal supports for the wrist-pin, also, appear in a plan view in this Fig. II. Fig. III is a fragmentaryview of my new adjustable piston showing in elevation the piston head, the journal box and its supports for the wrist-pin and the threaded studs in the upper edge of said supports. In Fig. IV is shown, in side elevation, that portion of my pistoncalled the movable part of the piston skirt, which is provided with upper and lower adjustment brackets.

Figure V is a plan view of one of the two similar stay-plates adapted to be used on the threaded studs in connection with the adjustment of the upper adjustment brackets as seen in Figs. II, VI and VII.

Figure VI is a vertical projection of the inside of my new piston with the wrist-pin, connecting rod, stay-plates, drift-pins and clamping nuts all removed to disclose the relative positions of various parts and features of my new piston when it has been set out to its extreme outward adjustment, in which are shown open spaces between the stationary part of the skirt and the movable part; and the oblong perforations in the upper and lower integral adjustment brackets are shown standing out on the sides of the threaded studs, toward which the movable part of the piston skirt has been drifted in its adjustment.

Figure VII is a detail, fragmentary view in section, showing the relative positions, of the wrist-pin journal box and its support, also, the threaded studs in the upper edge thereof and the upper adjustment brackets with their oblong adjustment perforations ushed to their extreme open adjustment by the threaded drift-pins and stay-plates, all

ready'to be held in their operative position v by the clamping. nuts adapted to fit on the I threaded studs. c

Figure VIII is fragmentary, sectional V view in detail showing part of the solid head of my-new piston holding the threaded stud over which the lower adjustment bracket has been placed and drifted to its extreme outer position by .means of the threaded drift-pin and stay-plate shown therein, all movable parts being held in their operative 15 positions by the clamping nut on the threadgjjtiOIl, arrangement and combination of parts in which all the foregoing objects have been attained. And, now, with the general purpose and these special objects aforesaid in view, I will proceed to describe my invention 5in detail, pointing out the new and usefulfeatures and explaining the uses and opera tions of the individual parts, combinations thereof, as illustrated in the drawing herein delineated in which similar characters refer 3 to similar parts throughout the. several views.

Referring to the drawing, the numeral 1 indicates the solid head of my piston and 2 points out the stationary part of the piston skirt integral with the head 1; while 3 refers 3 5 to the adjustable part of the piston skirt and a marks the seam or joint between the two parts of the piston skirt. The numeral 5 indicates the wrist-pin to which the connecting rod 7 is operatively attached and 5a is the journal box of the wrist-pin 5, integral with its supports 6, 6, in the upper edges of which are fixed the threaded anchor studs 6a, 6a, which are adapted to take and hold in place the upper adjustment brackets 9, 9, integral with the adjustable part 3 of the piston skirt,

as shown in Figs. II, VI and VII; while the threaded anchor stud 1b fixed in the boss 1a in the inside center of the solid head 1, takes and holds in operative position the lower ad- 5 justment bracket of the adjustable part 3 of the piston skirt, as shown in Figs. II, VI and VIII. 7

Now in order that we may adjust the movable part 3 of the piston skirt inward or outward to compensate for the usual wear of v the parts in service, I have provided two oblong perforations 9a, 9a, in each one of the upper adjustment brackets, which fit loosely on over the anchor studs 6a, 6a, and one an oblong perforation 8a near the end of the lower adjustment bracket 8, as shown in Figs. VI,- VII and VIII. These oblong perforations allow us to move the adjustable part 3 of the piston skirt outward to a limited as extent; and to do this easily I have provided two stay-plates 10, 10, for the upper brackets 9, 9, adapted, with perforations 100, 100 to fit closely on the threaded anchor studs 6a, 6a, and rest on top of the brackets. 9, 9, as shown in Fig. VII. And I have provided another shorter stay-plate 11 for the lower bracket 8,

adapted, with one perforation 11a near the inner end, to fit closely on the threaded stud 1?) on top of bracket 8, and with a guide lug 11?) on the outer end designed to fit into a guide-slot 8?) cut into the upper surface of the bracket 8 and adapted to keep the stayplate ll from swinging sidewise when it is in its normal operative position fitted on over the stud 1b and resting on the upper surface ofthe bracket 8 in its normal service position, as shown in FigVIII.

Now, these stay-plates fit snugly over the threaded anchor studs and do not slide any way; but the brackets under them, in their service position, do slidewithin a definite limit, for the desirable adjustment of the movable part 3 of the piston skirt; so, in connection with these stay plates, Ihave pro-' vided a novel means, adapted to movecares fully the upper and lower bracketoutward a predetermined distance in the adjustment of the piston, by fastening on the upper sides of the centers of the stay-plates 10, 10, metal bosses 106 with screw holes drilled, tapped all the way down through the stay-plates and adapted to take the threaded drift-pins 10a, 10a, which are provided with slotted screw heads and cone-shaped ends and lock nuts 10b, 10b adapted to hold the threaded drift-pins set in place. And nearly in line with these threadeddrift-pinslOa, 10a, I have made drifteborings 9Z9, 9?) in the upper surface of the adjustment brackets 9, 9, in such a position that, when the threaded driftpins 10a, 10a are screwed down a certain'distance, the tapering sides of the cone-shaped ends of the drift-pins will contact with the outer edges of the drift-borings and force the brackets outward a predetermined distance, for the desired adjustment of the movable part 3 of the piston skirt. 7 I

And in case of the lower adjustment bracket 8 and its stay-plate 11, I have provided a similar arrangement in fastening a metal boss 11@ on theupper side of the stayplate 11 and fitting a threaded drift-pin down through the boss and the stay-plate 11,

with the cone-shaped end of the drift-pin 110 adapted to be screwed down to contact with the outer edge of the drift-boring 8c in the upper surface of the adjustment bracket '8, so as to force this lower bracket outward a predetermined distance to set the outer cylindrical surface of the movable part 3 of the piston skirt parallel with the stationary part integral with the piston head 1. And for this threaded drift-pin 110 I have provided a lock nut 1161 to hold it in place after it is set, And a clamping nut 1d screwed Cir down tightly on the anchor stud 1?) holds the stay-plate 11 and bracket 8 securely in place for normal service, as shown in Fig. VIII.

Now, to understand the utility and eiiiciency of my new adjustable piston for gasoline engines, we should put it into service in the following way:

lVe should select such a size of my new pistons as will normally fit the cylinders of our engine, when the movable part 3 of the piston skirt is set all the way in, as illustrated in Fig. I. And after a long period of service, these pistons will show more or less wear along the sides of the skirt over a greater or less extent of arc, the mildle of the worn places being out at rightangl.es to the axis of the wrist-pin, And when these parts or the contiguous parts of cylinder walls in which the pistons are sliding, have become so worn as to give evidence of ineificiency in service, we should remove the pistons from the cylinders and slightly loosen the clamping nuts 10d, 10d of the upper adjustment bracket 9 and, also, the lock nuts 10?), 10?); then loosen the clamping nut 1d and the lock nut 11d of the lower bracket 8; and then screw the driftpins 10a, 10a and 110 down against the outer edges of the drift-borings 9b, 9b and 80 just hard enough to push the adjustment brackets 9, 9, and 8 outward and thus force the movable part 3 of the piston skirt outward far enough to compensate for the wear of the parts in service up to the present time, being careful to set the cylindrical surface of the movable part 3 of the piston skirt parallel with the cylindrical surface of the stationery part 2 of the piston skirt. We should then screw down tightly the clamping nuts 10d, 10d and lcZ and also set down the lock nuts 10b, 10b and 110; and then reassemble the piston and replace it.

In actual service I have found that my new pistons thus adjusted; will function efficiently for another long period and then 1 they can be adjusted again to compensate for further wear, until we reach a practicable limit. And thus I have found my new pistons more economical than other types of pistons for gasoline engines.

And, now, having thus described the various features of my invention, the detail construction, arrangement and combination of its parts as well as its functions and ways and means of operation; those features and combinations of my invention that I consider new and useful and representative of utility and e'lficiency, on which I desire Letters Patent granted to me, I have hereinbefore set forth and specifically described in the following claims 1. In a piston for gasoline engines, adapted to be adjusted within practicable limits: a iston head having annular grooves around it for carrying packing rings; a divided piston skirt composed of two separate parts, one

part being integral with the piston head and the other part being detachable and adjustable when mounted in its operative position in the piston; upper and lower brackets on the detachable part of the piston skirt, provided with perforations and borings adapted for the attachment and the adjustment of the said detachable part on the'main part of the piston for normal operation in service; rigid supports carrying threaded lugs inside said piston head adapted to hold said adjustment brackets in position for service and adjust-V ment; stay-plates adapted to fit closelyon over said threaded lugs and provided with threaded drift-pins having conical ends and adapted to be screwed down through the stayplates and to contact with the outer edges of V the drift-borings in theupper sides of the adjustment brackets so as to force the movable part of the piston skirt out far enough to compensate for the wear thereon in normal service; lock nuts for securely holding the threaded drift-pins after they are set down; and clamping nuts adapted to hold the stay-plates and the adjustment brackets securely in place after they have been set in their operative positions for service, substantially as hereinabove described.

2. In a piston designed for use in gasoline engines: a solid head adapted to carry pistonpacking rings around it; two integral brackets mounted on the inner part of said head and adapted to hold operatively the wristpin of the connecting rod; a divided piston skirt, one part of which being integral with the piston head and the other part being separate from the piston head and adjustable and practically equal in length and circumference to the former part; two pairs of threaded anchor studs fixed in the upper edges of said brackets, and one in the inner central part of the piston head; upper and lower adjustment brackets integral with said adjustable part of the piston skirt and adapted to fit on over said anchor studs to hold the adjustable part of the piston skirt in its operative position; means for adjusting the movable part of the skirt to a predetermined position to compensate for the wear of the parts involved; and means for holding the movable part of the skirt securely for normal operation in the desirable position of adjustment.

3. A cylindrical piston for gasoline engines, consisting of a solid cylindrical piston head having annular grooves around it for holding packing rings; a practically semicylindrical portion of a piston skirt integral with said head and forming a part of the body of the piston; another practically semicylindrical portion of a piston skirt separate from said piston head and provided with upper and lower attachment brackets designed for fastening said separate portion in its operative position onto the piston head; threaded anchor studs fixed in the integral parts of thepiston' head; elongated perforations in said upper and lower attachment brackets adapted to fit on over said threaded anchor studs in such a manner as to allow an 5 adjusting movement of said adjustment brackets at right angles to the axis of the piston; and means coacting With said adjustment brackets and adapted to move and hold the adjustable skirt in a predetermined position to compensate for the Wear of the parts in normal service.

4; A piston comprising a head portion and a divided skirt portion, said skirt portion having a movable section adjustably mounted V with respect to the remainder of said piston,

an adjustable drift pin cooperating With said movable section to effect adjustment of the same relative to the remainder of said piston, and means for securing said movable section in adjusted position.

In testimony whereof I have hereunto set my signature.

JOHN N. LITTRELL. 

